| 1337 A Study of Additional Composite Resin Restoration for Repair | ||
|
H. MIYAJI, Y. HATSUOKA, O. TAKEUCHI, and K. YAMAMOTO, Osaka Dental University, Japan Objectives: The purpose of this study was to investigate the possibility of additional resin placement to worn or fractured composite resin restorations concerning the polymerization ratio in composites adherent with or without silane coupling treatment. Methods: Two light-cured composites (Clearfil® APX and Clearfil® ST, Kuraray) were cured into cylindrical specimens with Φ4×4mm. The specimens were immersed for 24 hours in 37°C water. In addition, some specimens were loaded repeatedly between 5 and 100kg for 10,000 times (5times/sec.) in 60°C water, and/or thermo cycling (5-55°C for 10,000 cycles) in water. The testing surfaces were ground 0-2.0mm from the exposed surface respectively. The Knoop hardness was measured as an index of the polymerization ratio in each depth. After the ultrasonic cleansing, the specimens were classified into two groups with/without silane coupling treatment (Clearfil® Porcelain Bond activator, Kuraray). Additional composites were filled after the bonding material (Bis-GMA/TEGDMA=60/40, wt%) was applied. The specimens were immersed in 37°C water for 24 hours, 1 month or loaded thermo cycling (5,000 cycles). The specimens were cut out into the dumbbell-shaped plates (bonding area: 1×1mm), and were measured for tensile bonding strength. A statistical analysis was performed using Scheffé's test and Student's t-test for all (p<0.05). Results: A tendency which the peak was 0.5-1.5mm for the Knoop hardness on the adherence surface was seen regardless of the type and the level of the load. The bonding strength to loaded composites improved in most cases of APX with silane coupling treatment. However, there was no significant difference between the presence of silane coupling or not in ST. Moreover, in most cases excluding the surface there was no remarkable increase or decrease of bonding strength according to the depth of grinding. Conclusion: Depending on the type of composite resin, silane coupling treatment in additional composite resin restoration improves bond strength. | ||
| Seq #158 - Composite Repair, Biocompatibility, Adhesive Interfaces 3:00 PM-4:00 PM, Friday, 10 March 2006 Dolphin Hotel Pacific Hall | ||
|
Back to the Dental Materials: II - Adhesion-Other Program
| ||